Method and system for detecting heavy metal pollution in soil sample

Abstract

The invention relates to the technical field of soil detection, and discloses a method and system for detecting heavy metal pollution in a soil sample, and the system comprises three modules: a data acquisition module, a data processing module and a state early warning module. The data acquisition module acquires soil samples at different depths in different preset areas, stores the soil samples in a pollution-free container, and marks sample sources. The data processing module is responsible for pretreatment and chemical analysis of samples, heavy metal signal intensity is measured by using an ion detector, heavy metal concentration is calculated, pollution level is further evaluated, and a result is sent to the state early warning module. The state early warning module judges whether the area is a sensitive area or not according to the evaluation result, and carries out secondary sampling and evaluation if necessary so as to correct the pollution level and decide whether to give out early warning or not. By calculating the heavy metal signal intensity, the blank signal intensity and the instrument sensitivity correction factor, the heavy metal concentration in the soil sample can be accurately calculated.

Description

Technical Field

[0001] The present invention relates to the technical field of soil detection, and in particular to a method and system for detecting heavy metal pollution in soil samples. Background Art

[0002] With the rapid development of industrialization, urbanization and agricultural activities, the problem of heavy metal pollution in soil is becoming increasingly serious. Heavy metals such as lead, cadmium, mercury and arsenic can accumulate through the food chain and eventually pose a major threat to human health. In addition, heavy metal pollution can also lead to a decrease in soil fertility and an imbalance in the ecosystem. Therefore, how to effectively monitor and evaluate heavy metal pollution in soil has become an important topic in the fields of scientific research and environmental protection.

[0003] Current heavy metal pollution detection methods mainly rely on laboratory analysis, which is usually time-consuming, costly, and requires complex sample pre-treatment steps. This not only limits the efficiency of detection, but also makes it difficult to meet the needs of large-scale soil pollution monitoring. More importantly, traditional detection methods are difficult to provide real-time and flexibility when faced with complex and changeable soil environments, which makes it difficult to quickly determine the exact source and scope of pollution, thus affecting subsequent governance and decision-making.

[0004] Therefore, developing a system that can quickly and accurately detect soil heavy metal pollution and provide real-time early warning is of great significance for improving environmental monitoring capabilities and implementing effective pollution control measures. Summary of the invention

[0005] In view of this, the present invention proposes a method and system for detecting heavy metal pollution in soil samples, aiming to solve the problem that traditional detection methods in current technology are difficult to provide real-time performance and flexibility when facing complex and changeable soil environments.

[0006] On the one hand, the present invention provides a system for detecting heavy metal pollution in soil samples, comprising:

[0007] The data acquisition module includes a collection device and a storage device. The collection device is arranged in each preset area. The depth of the data acquisition module in different preset areas is different. After collecting the soil sample, the soil sample is stored in the storage device. The storage device is a pollution-free container, and a marking signal representing the area where the sample is located is arranged on the outside of the storage device.

[0008] A data processing module, the data processing module is used to pre-process and chemically analyze the soil sample, detect the heavy metal signal intensity of the soil sample through an ion detector, calculate the heavy metal concentration in the soil sample according to the heavy metal signal intensity, evaluate the pollution level according to the heavy metal concentration and the heavy metal concentration standard limit, and send the evaluation result to the status warning module;

[0009] A status warning module is connected to the data acquisition module and the data processing module respectively. The status warning module is configured to determine whether the area corresponding to the evaluation result is a sensitive area according to the evaluation result. When the evaluation result determines that the pollution level of the area corresponding to the evaluation result is too high, the area is set as a sensitive area, and the soil in the sensitive area is randomly sampled for a second time, and soil samples at different depths are selected for a second evaluation. According to the second evaluation result, the initial pollution level of the sensitive area is corrected to obtain a final pollution level, and whether to issue a warning is determined according to the final pollution level.

[0010] Optionally, the pre-processing of the soil sample specifically includes:

[0011] The soil sample was dried at low temperature to constant weight, and then crushed into 200 mesh powder;

[0012] Using microwave digestion method, the powder sample was digested in a mixed system of concentrated nitric acid and hydrofluoric acid to completely dissolve the metal powder in the soil sample. The digestion solution was filtered through filter paper and diluted to a specific volume to obtain the digestion solution dilution volume. Prepare for chemical analysis.

[0013] Optionally, the calculation of the heavy metal concentration in the soil sample by the heavy metal signal intensity is specifically:

[0014] Calculate blank signal intensity and instrument sensitivity correction factor;

[0015] The calculation of blank signal intensity specifically includes measuring the signal response of a blank sample solution using the same instrument and conditions as those used to detect the soil sample; the blank sample is a reagent or matrix that does not contain heavy metals;

[0016] The calculation method of the instrument sensitivity correction factor specifically includes:

[0017] Prepare multiple standard solutions of different known concentrations to cover the concentration range of the sample to be tested, use an instrument to measure the signal intensity of each standard solution, and draw a calibration curve of concentration versus signal intensity. The slope is the instrument sensitivity, and the instrument sensitivity correction factor F is the reciprocal of the instrument sensitivity.

[0018] Optionally, the heavy metal concentration in the soil sample is calculated using the following formula:

[0019] ;

[0020] in, Indicates the heavy metal concentration, Indicates the signal strength of heavy metals. Indicates the blank signal strength, represents the volume of digestion solution dilution, F represents the instrument sensitivity correction factor, m represents the sample mass, Indicates the sample volume.

[0021] Optionally, evaluating the pollution level by using the heavy metal concentration and the heavy metal concentration standard limit value specifically includes:

[0022] The pollution level is divided by a preset gradient heavy metal pollution comprehensive index Pi, the heavy metal pollution comprehensive index is calculated by the heavy metal concentration and the heavy metal concentration standard limit, and the pollution level is determined by judging the size relationship between the heavy metal pollution comprehensive index and the preset heavy metal pollution comprehensive index.

[0023] Optionally, the classification of pollution levels by presetting the gradient heavy metal pollution comprehensive index Pi specifically includes:

[0024] Pi less than 1.0 indicates that the area where the current soil sample is located is free of pollution;

[0025] Pi greater than or equal to 1.0 and less than 2.0 indicates that the area where the current soil sample is located is slightly polluted;

[0026] Pi greater than or equal to 2.0 and less than 3.0 indicates that the area where the current soil sample is located is moderately polluted;

[0027] Pi greater than or equal to 3.0 indicates that the area where the current soil sample is located is severely polluted.

[0028] Optionally, the calculation formula of the comprehensive heavy metal pollution index Pi is:

[0029] ;

[0030] Wherein, Pi represents the comprehensive index of heavy metal pollution, represents the measured concentration of the nth heavy metal; is the standard limit value of the nth heavy metal, and n is the number of heavy metal types.

[0031] Optionally, the secondary random sampling of the soil in the sensitive area and the selection of soil samples at different depths for secondary evaluation specifically include:

[0032] Sampling is carried out multiple times in the sensitive area, the average heavy metal concentration is calculated, and the comprehensive heavy metal pollution index is calculated again based on the average heavy metal concentration to obtain the secondary heavy metal pollution comprehensive index. The secondary pollution level is calculated based on the secondary heavy metal pollution comprehensive index. If the secondary pollution level is greater than or equal to the primary pollution level, an early warning signal is issued based on the secondary pollution level.

[0033] Optionally, the calculation formula for the average heavy metal concentration is:

[0034] ;

[0035] Among them, the represents the average heavy metal concentration, m is the number of samples, Represents the concentration of the i-th heavy metal in the j-th sample.

[0036] On the other hand, the present invention also proposes a method for the heavy metal pollution detection system in the soil sample, the method comprising:

[0037] After collecting the soil sample, the soil sample is stored in a storage device, wherein the storage device is a pollution-free container, and a marking signal representing the area where the sample is located is arranged on the outside of the storage device;

[0038] The soil sample is pretreated and chemically analyzed, the heavy metal signal intensity of the soil sample is detected by an ion detector, the heavy metal concentration in the soil sample is calculated by the heavy metal signal intensity, and the pollution level is evaluated by the heavy metal concentration and the standard limit of heavy metal concentration;

[0039] Determine whether the area corresponding to the assessment result is a sensitive area based on the assessment result. When the assessment result determines that the pollution level in the area corresponding to the assessment result is too high, set this area as a sensitive area, conduct a secondary random sampling of the soil in the sensitive area, and select soil samples at different depths for secondary assessment. According to the secondary assessment result, correct the initial pollution level of the sensitive area to obtain the final pollution level, and determine whether to issue an early warning based on the final pollution level.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a system and method for detecting heavy metal pollution in soil samples, the data acquisition module in the system is scientifically designed, and soil samples can be collected at different depths. The collection depth of each preset area is adjustable, which ensures the representativeness of the sample. The collected soil samples are stored in pollution-free containers, and the sample source information is marked on the outside of the container to ensure the integrity and traceability of the sample storage. The data processing module accurately detects the signal intensity of heavy metals through preprocessing and chemical analysis, combined with an ion detector. By calculating the signal intensity of heavy metals, the blank signal intensity and the instrument sensitivity correction factor, the heavy metal concentration in the soil sample can be accurately calculated. This high-precision detection and analysis method effectively improves the accuracy of pollution level assessment. The status warning module can quickly determine whether the soil area is a sensitive area based on the assessment results. For plots identified as sensitive areas, the system will automatically perform secondary random sampling and select samples at different depths for re-evaluation. Using the preset comprehensive index of heavy metal pollution, the system can correct the preliminary assessment results to ensure that the final pollution level is determined more accurately. When the secondary assessment results show that the pollution level is high, the system will issue a warning signal so that corresponding emergency measures can be taken. The system realizes the whole process automation from sample collection to data analysis and result evaluation, reduces the possibility of human error, and improves the detection speed and efficiency. The system is easy to operate and suitable for heavy metal pollution detection in different regions and environmental conditions. This system can be widely used in environmental monitoring agencies, agricultural departments, soil research units, etc., to provide efficient soil heavy metal pollution monitoring services. Provide reliable data support for policy makers and environmental protection departments to facilitate the formulation and implementation of scientific pollution control and remediation strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0042] Figure 1 A framework diagram of a heavy metal pollution detection system in soil samples provided by an embodiment of the present invention;

[0043] Figure 2 A flow chart of a method for detecting heavy metal pollution in soil samples provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0045] like Figure 1 As shown in FIG. 1 , it is a framework diagram of a heavy metal pollution detection system in soil samples proposed by the present invention. It can be seen that the system includes:

[0046] The data acquisition module includes a collection device and a storage device. The collection device is arranged in each preset area. The depth of the data acquisition module in different preset areas is different. After collecting the soil sample, the soil sample is stored in the storage device. The storage device is a pollution-free container, and a marking signal representing the area where the sample is located is arranged on the outside of the storage device;

[0047] Data processing module: The data processing module is used to pre-process and chemically analyze soil samples, detect the heavy metal signal intensity of soil samples through an ion detector, calculate the heavy metal concentration in the soil sample through the heavy metal signal intensity, evaluate the pollution level through the heavy metal concentration and the standard limit of heavy metal concentration, and send the evaluation results to the status warning module;

[0048] The status warning module is connected to the data acquisition module and the data processing module respectively. The status warning module is configured to determine whether the area corresponding to the evaluation result is a sensitive area based on the evaluation result. When the evaluation result determines that the pollution level of the area corresponding to the evaluation result is too high, this area is set as a sensitive area, and the soil in the sensitive area is randomly sampled for the second time, and soil samples at different depths are selected for secondary evaluation. According to the secondary evaluation result, the initial pollution level of the sensitive area is corrected to obtain the final pollution level, and whether to issue an early warning is determined according to the final pollution level.

[0049] It can be understood that the heavy metal pollution detection system in soil samples realizes the accurate collection, analysis and early warning of soil samples through the collaboration of three key modules. First, the data acquisition module uses the acquisition device to sample in different preset areas, and sets different sampling depths according to local conditions to ensure the representativeness and accuracy of the samples. The collected soil samples are stored in a pollution-free storage device with a marking signal to ensure the traceability of the source of the samples. Next, the data processing module pre-treats and chemically analyzes the soil samples, and uses an ion detector to measure the signal intensity of heavy metals. Through this signal intensity, the concentration of heavy metals in the soil is calculated and compared with the standard limit to evaluate the pollution level. This sophisticated analysis step ensures an accurate assessment of the soil pollution situation. The status warning module determines whether the area is a sensitive area based on the evaluation results sent by the data processing module. When the pollution level of a certain area is determined to be too high, the area will be marked as a sensitive area. In order to ensure the accuracy of the evaluation, the system will perform secondary random sampling in sensitive areas and obtain samples from different depths for re-evaluation. In this way, the pollution level of the initial evaluation is corrected to obtain a more accurate final pollution level. Once the final pollution level is determined, the system will determine whether an early warning signal is needed based on the result. This multi-level evaluation and early warning mechanism ensures the system's high sensitivity and reliability in detecting heavy metal pollution, and helps to identify and respond to potential environmental threats in a timely manner. Through close cooperation between modules, the system has demonstrated remarkable efficiency and accuracy in the detection, evaluation and management of soil heavy metal pollution.

[0050] Through the designed data acquisition module, soil samples can be collected at different depths and stored in pollution-free containers, effectively avoiding secondary contamination of samples during collection and storage. The data processing module equipped with the system uses advanced chemical analysis technology and ion detectors to achieve high-precision detection of heavy metal signal intensity, and obtains soil heavy metal concentrations through precise calculations, so as to accurately assess the pollution level. The status warning module can judge the sensitivity of the soil area in real time according to the evaluation results, and conduct secondary random sampling and evaluation at different depths when necessary. This function ensures accurate correction of the pollution level and can issue early warning signals in time, effectively reducing the potential risk of heavy metal pollution. The entire system has a high degree of automation, from sample collection, preprocessing to data analysis, result evaluation and early warning, all of which can be completed automatically, reducing the errors caused by human operation and improving detection efficiency and reliability.

[0051] In this preferred embodiment, pre-processing the soil sample specifically includes:

[0052] The soil samples were dried at low temperature to constant weight and then crushed into 200 mesh powder;

[0053] Using microwave digestion method, the powder sample was digested in a mixed system of concentrated nitric acid and hydrofluoric acid to completely dissolve the metal powder in the soil sample. The digestion solution was filtered through filter paper and diluted to a specific volume to obtain the digestion solution dilution volume. Prepare for chemical analysis.

[0054] It is understood that the soil sample is dried to a constant weight under low temperature conditions, which can remove moisture from the sample and ensure the accuracy of subsequent analytical results. The dried sample is then crushed into a 200 mesh size powder to increase the surface area for more efficient digestion. Microwave digestion technology is used to treat the powder sample in a mixed system of concentrated nitric acid and hydrofluoric acid. The purpose of this step is to completely dissolve the heavy metal elements in the soil for subsequent detection and analysis. Microwave digestion is an efficient and rapid method that can evenly heat the sample and improve the digestion efficiency. The digested liquid is filtered through filter paper to remove insoluble impurities. The filtered solution is then diluted to a specific volume to ensure that the heavy metal concentration in the solution is suitable for subsequent chemical analysis. This step allows the sample to reach a concentration range suitable for detection by the analytical instrument while ensuring the reliability and accuracy of the analytical results.

[0055] It is understandable that by pre-treating the soil samples, the system can provide a more accurate and reliable basis for subsequent chemical analysis. First, the soil samples are dried to constant weight at low temperature to ensure that the water in the samples is completely removed, which helps to improve the consistency and accuracy of the analysis results. The dried samples are crushed into 200 mesh powders. Such refinement increases the specific surface area of ​​the samples and ensures the adequacy of the subsequent digestion process. The use of microwave digestion to treat the powdered samples is to efficiently and quickly dissolve the metal components in the soil in a mixed system of concentrated nitric acid and hydrofluoric acid. Microwave digestion, due to its efficient and uniform heating characteristics, makes the digestion process of the samples more thorough and reduces the problem of incomplete digestion that may exist in traditional methods. Through this method, the metal powder in the sample can be completely dissolved, providing an accurate material basis for analysis. After the digestion is completed, filtering the digestion solution with filter paper can effectively remove the undigested residue and ensure the purity of the solution. The filtrate is then diluted to a specific volume, a step that not only makes the concentration suitable for the detection range of the subsequent analytical instrument, but also ensures the comparability and standardization of the results, providing stable sample conditions for subsequent chemical analysis. Overall, through this pretreatment method, the system effectively improves the analytical accuracy and efficiency of soil samples and ensures the reliability and repeatability of the test results. This meticulous pretreatment step lays the foundation for accurate heavy metal content detection and is an important link in achieving accurate environmental monitoring and assessment.

[0056] In this preferred embodiment, the heavy metal concentration in the soil sample is calculated by the heavy metal signal intensity as follows:

[0057] Calculate blank signal intensity and instrument sensitivity correction factor;

[0058] Calculating the blank signal intensity specifically includes measuring the signal response of a blank sample solution using the same instrument and conditions as those used to test the soil sample; the blank sample is a reagent or matrix that does not contain heavy metals;

[0059] The calculation method of the instrument sensitivity correction factor specifically includes:

[0060] Prepare multiple standard solutions of different known concentrations to cover the concentration range of the sample to be tested. Use the instrument to measure the signal intensity of each standard solution and draw a calibration curve of concentration versus signal intensity. The slope is the instrument sensitivity, and the instrument sensitivity correction factor F is the reciprocal of the instrument sensitivity.

[0061] It can be understood that the blank signal intensity is calculated by measuring the signal response of the blank sample solution using the same instrument and conditions as the soil sample. The blank sample is a reagent or matrix that does not contain heavy metals and is used to eliminate the impact of background signals on the measurement results. The instrument sensitivity correction factor is calculated by preparing multiple standard solutions of known concentrations, which should cover the concentration range of the sample to be tested. The signal intensity of each standard solution is measured using the instrument. A calibration curve of concentration and signal intensity is plotted, and the slope of the curve represents the sensitivity of the instrument. The instrument sensitivity correction factor (F) is the reciprocal of this slope and is used to correct for differences in the sensitivity of the measurement.

[0062] Through these steps, the concentration of heavy metals in soil samples can be accurately calculated. The measurement of blank signal intensity ensures the minimization of background effects, while the introduction of instrument sensitivity correction factors ensures the consistency and accuracy of the measurements.

[0063] In this preferred embodiment, the heavy metal concentration in the soil sample is calculated by the following formula:

[0064] ;

[0065] in, Indicates the heavy metal concentration, Indicates the signal strength of heavy metals. Indicates the blank signal strength, represents the volume of digestion solution dilution, F represents the instrument sensitivity correction factor, m represents the sample mass, Indicates the sample volume.

[0066] In this preferred embodiment, evaluating the pollution level by heavy metal concentration and heavy metal concentration standard limit specifically includes:

[0067] The pollution level is divided by a preset gradient heavy metal pollution comprehensive index Pi, the heavy metal pollution comprehensive index is calculated by the heavy metal concentration and the heavy metal concentration standard limit, and the pollution level is determined by judging the relationship between the heavy metal pollution comprehensive index and the preset heavy metal pollution comprehensive index.

[0068] It is understandable that by using heavy metal concentrations and standard limits to assess pollution levels, the system can achieve more accurate environmental monitoring. The preset gradient heavy metal pollution comprehensive index Pi provides a clear scale for the classification of pollution levels. By calculating the ratio of the current heavy metal concentration to its standard limit, the system can generate a comprehensive index that reflects the degree of heavy metal pollution. This method not only relies on a single heavy metal concentration data, but also combines the standard limit to ensure the scientificity and rationality of the assessment results. By comparing the heavy metal pollution comprehensive index with the preset index, the system can quickly determine the pollution level. Such a comparison process helps to identify the severity and potential hazards of pollution, so that environmental health risks can be more accurately assessed. In this preferred embodiment, the use of the pollution comprehensive index to divide the pollution level can effectively reduce the errors caused by subjective judgment. The index standard of the preset gradient sets an objective baseline for pollution assessment, making the judgment process more transparent and verifiable. Through this standardized assessment method, the system can ensure that the pollution level classification is consistent regardless of the environmental conditions. In this way, the system not only improves the accuracy of pollution monitoring, but also enhances the stability and reliability of data analysis. In addition, the use of a comprehensive index for assessment can also promote long-term environmental monitoring and data accumulation. By continuously recording and analyzing the relationship between heavy metal concentrations and standard limits, the system can track pollution trends and changes, and provide reliable data support for the formulation of long-term environmental management strategies. The accumulation and analysis of such data helps to discover potential pollution sources and pollution incidents, and provides a scientific basis for decision-making. Through the calculation and comparison of heavy metal concentrations and standard limits, the system demonstrates higher accuracy and consistency in pollution level assessment, providing strong support for environmental risk management. This method not only improves the effectiveness of the pollution monitoring system, but also provides an important data basis for scientific decision-making and optimal resource allocation. Through this precise evaluation mechanism, the system can better serve environmental protection and public health and safety.

[0069] In this preferred embodiment, the classification of pollution levels by presetting the gradient heavy metal pollution comprehensive index Pi specifically includes:

[0070] Pi less than 1.0 indicates that the area where the current soil sample is located is free of pollution;

[0071] Pi greater than or equal to 1.0 and less than 2.0 indicates that the area where the current soil sample is located is slightly polluted;

[0072] Pi greater than or equal to 2.0 and less than 3.0 indicates that the area where the current soil sample is located is moderately polluted;

[0073] Pi greater than or equal to 3.0 indicates that the area where the current soil sample is located is severely polluted.

[0074] It is understandable that taking appropriate measures according to different heavy metal pollution levels can help effectively manage and mitigate the impact of pollution on the environment and health. The following are some measures for different pollution levels:

[0075] 1. No pollution (Pi < 1.0)

[0076] Monitoring and maintenance: Continue regular monitoring to ensure that pollution levels remain within safe limits. Encourage sustainable land management practices and prevent the introduction of new sources of pollution.

[0077] 2. Mild pollution (1.0≤Pi<2.0)

[0078] Monitoring and Control: Increase monitoring frequency to observe changes in pollutant levels. Identify and control potential sources of pollution to prevent further pollution. Raise awareness among the public and land users about low-level pollution and how to control it.

[0079] 3. Moderate pollution (2.0≤Pi<3.0)

[0080] Management and remediation: Conduct detailed risk assessments to assess the risks of contamination to ecosystems and human health. Implement medium-intensity soil remediation techniques, such as phytoremediation (the use of specific plants to absorb and fix heavy metals). Restrict sensitive uses, such as agricultural production, especially food crops, in affected areas. Work with communities and local governments to develop pollution control and remediation plans.

[0081] 4. Severe pollution (Pi ≥ 3.0)

[0082] Emergency control and remediation: Take immediate emergency measures to prevent further spread of contamination, such as using physical barriers or chemical stabilizers. Implement high-intensity remediation technologies, such as chemical leaching, soil replacement, or thermal desorption. Conduct health risk assessments for potentially affected residents and provide appropriate medical support. Develop and implement stricter pollution control regulations to ensure that responsible parties assume responsibility for control and remediation. Establish a long-term monitoring and evaluation plan to ensure the effectiveness of remediation and prevent recurrence of contamination.

[0083] In this preferred embodiment, the calculation formula of the comprehensive index of heavy metal pollution Pi is:

[0084] ;

[0085] Among them, Pi represents the comprehensive index of heavy metal pollution, represents the measured concentration of the nth heavy metal; is the standard limit value of the nth heavy metal, and n is the number of heavy metal types.

[0086] In this preferred embodiment, the soil in the sensitive area is randomly sampled twice, and soil samples at different depths are selected for secondary evaluation, specifically including:

[0087] Sampling is carried out multiple times in the sensitive area, the average heavy metal concentration is calculated, and the comprehensive heavy metal pollution index is calculated again based on the average heavy metal concentration to obtain the secondary heavy metal pollution comprehensive index. The secondary pollution level is calculated based on the secondary heavy metal pollution comprehensive index. If the secondary pollution level is greater than or equal to the initial pollution level, an early warning signal is issued based on the secondary pollution level.

[0088] It is understandable that by conducting secondary random sampling in sensitive areas and obtaining soil samples from different depths for evaluation, the system can obtain more comprehensive and accurate information on the heavy metal pollution status. The combination of multiple sampling and deep analysis reduces the possible errors in the single measurement of samples and improves the reliability of the data. By calculating the average value of heavy metal concentrations and recalculating the comprehensive index of heavy metal pollution based on this average value, the system can conduct a deeper analysis of the pollution status. This process ensures that the evaluation of heavy metal concentrations in the soil is not just superficial, but deeply considers the pollution at different depths. By generating a secondary comprehensive index of heavy metal pollution, the system can compare and analyze the current pollution status with the initial assessment. When the secondary pollution level is greater than or equal to the initial pollution level, it means that the pollution status may intensify or persist, and thus needs to be paid attention to. The early warning signal issued by the system based on the secondary pollution level helps to take necessary environmental protection measures in time to prevent further spread of pollution. This early warning mechanism ensures the initiative and timeliness of environmental management, enabling the monitoring system to respond quickly to potential crises. In addition, this secondary sampling and evaluation method helps to monitor pollution trends over a long period of time. By analyzing sensitive areas multiple times and at different depths, the system can identify potential pollution sources and spatial distribution characteristics, providing a scientific basis for formulating more effective environmental governance strategies. This detailed assessment process not only enhances the depth and breadth of the data, but also improves the accuracy of environmental risk assessment. Overall, through secondary random sampling and recalculation of the comprehensive index, the system has demonstrated greater accuracy and sensitivity in monitoring soil heavy metal pollution.

[0089] In this preferred embodiment, the calculation formula for the average heavy metal concentration is:

[0090] ;

[0091] in, represents the average heavy metal concentration, m is the number of samples, Represents the concentration of the i-th heavy metal in the j-th sample.

[0092] In summary, the present invention provides a system and method for detecting heavy metal pollution in soil samples. The data acquisition module in the system is scientifically designed and can collect soil samples at different depths. The collection depth of each preset area is adjustable to ensure the representativeness of the sample. The collected soil samples are stored in pollution-free containers, and the sample source information is marked on the outside of the container to ensure the integrity and traceability of the sample storage. The data processing module performs accurate detection of the heavy metal signal intensity through pretreatment and chemical analysis in combination with an ion detector. By calculating the heavy metal signal intensity, blank signal intensity and instrument sensitivity correction factor, the heavy metal concentration in the soil sample can be accurately calculated. This high-precision detection and analysis method effectively improves the accuracy of pollution level assessment. The status warning module can quickly determine whether the soil area is a sensitive area based on the assessment results. For plots identified as sensitive areas, the system will automatically perform secondary random sampling and select samples at different depths for re-evaluation. Using the preset heavy metal pollution comprehensive index, the system can correct the preliminary assessment results to ensure that the final pollution level is determined more accurately. When the secondary assessment results show that the pollution level is high, the system will issue a warning signal so that corresponding emergency measures can be taken. The system realizes the whole process automation from sample collection to data analysis and result evaluation, reduces the possibility of human error, and improves the detection speed and efficiency. The system is easy to operate and suitable for heavy metal pollution detection in different regions and environmental conditions. This system can be widely used in environmental monitoring agencies, agricultural departments, soil research units, etc., to provide efficient soil heavy metal pollution monitoring services. Provide reliable data support for policy makers and environmental protection departments to facilitate the formulation and implementation of scientific pollution control and remediation strategies.

[0093] On the other hand, see Figure 2 The present invention also proposes a method for the heavy metal pollution detection system in the soil sample, the method comprising:

[0094] S1: After collecting the soil sample, the soil sample is stored in a storage device, which is a non-polluting container, and a marking signal representing the area where the sample is located is set on the outside of the storage device;

[0095] S2: Pre-treat and chemically analyze the soil samples, detect the heavy metal signal intensity of the soil samples using an ion detector, calculate the heavy metal concentration in the soil samples based on the heavy metal signal intensity, and evaluate the pollution level based on the heavy metal concentration and the standard limit of heavy metal concentration;

[0096] S3: Determine whether the area corresponding to the assessment results is a sensitive area based on the assessment results. When the assessment results determine that the pollution level in the area corresponding to the assessment results is too high, set this area as a sensitive area, conduct a secondary random sampling of the soil in the sensitive area, and select soil samples at different depths for secondary assessment. According to the secondary assessment results, correct the initial pollution level of the sensitive area to obtain the final pollution level, and determine whether to issue an early warning based on the final pollution level.

[0097] It is understandable that this method systematically detects heavy metal contamination in soil samples. The collected soil samples are stored in non-polluting containers to ensure that the samples are not affected by external contamination during storage and transportation. At the same time, the outside of the container is marked with a marking signal representing the area where the sample is located to facilitate tracking and management of the source of the sample. The soil samples undergo pretreatment and chemical analysis steps to ensure that the samples are in the best condition before entering the detection stage. The sample is tested for heavy metal signal intensity using an ion detector, and the signal intensity is used to calculate the heavy metal concentration in the sample. By comparing the measured heavy metal concentration with the standard limit, the system evaluates the pollution level. This step determines whether the pollution in the area meets a certain standard or threshold. If the evaluation results show that the pollution level in a certain area is too high, the area is marked as a sensitive area. At this time, a second random sampling is required in the area, and samples are collected from different depths for a second evaluation. Through this in-depth analysis, the scope and severity of the pollution can be more accurately understood. Based on the results of the second evaluation, the pollution level of the first evaluation will be revised to obtain the final pollution level. This final level is used to determine whether an early warning signal is needed to indicate the necessity of relevant measures. Overall, this method ensures the accuracy of heavy metal pollution detection and assessment through systematic and scientific steps, through multi-stage and multi-level analysis.

[0098] In summary, the present invention provides a system and method for detecting heavy metal pollution in soil samples. The data acquisition module in the system is scientifically designed and can collect soil samples at different depths. The collection depth of each preset area is adjustable to ensure the representativeness of the sample. The collected soil samples are stored in pollution-free containers, and the sample source information is marked on the outside of the container to ensure the integrity and traceability of the sample storage. The data processing module performs accurate detection of the heavy metal signal intensity through pretreatment and chemical analysis in combination with an ion detector. By calculating the heavy metal signal intensity, blank signal intensity and instrument sensitivity correction factor, the heavy metal concentration in the soil sample can be accurately calculated. This high-precision detection and analysis method effectively improves the accuracy of pollution level assessment. The status warning module can quickly determine whether the soil area is a sensitive area based on the assessment results. For plots identified as sensitive areas, the system will automatically perform secondary random sampling and select samples at different depths for re-evaluation. Using the preset heavy metal pollution comprehensive index, the system can correct the preliminary assessment results to ensure that the final pollution level is determined more accurately. When the secondary assessment results show that the pollution level is high, the system will issue a warning signal so that corresponding emergency measures can be taken. The system realizes the whole process automation from sample collection to data analysis and result evaluation, reduces the possibility of human error, and improves the detection speed and efficiency. The system is easy to operate and suitable for heavy metal pollution detection in different regions and environmental conditions. This system can be widely used in environmental monitoring agencies, agricultural departments, soil research units, etc., to provide efficient soil heavy metal pollution monitoring services. Provide reliable data support for policy makers and environmental protection departments to facilitate the formulation and implementation of scientific pollution control and remediation strategies.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A heavy metal pollution detection system in soil samples, characterized in that: include: The data acquisition module includes a collection device and a storage device. The collection device is arranged in each preset area. The depth of the data acquisition module in different preset areas is different. After collecting the soil sample, the soil sample is stored in the storage device. The storage device is a pollution-free container, and a marking signal representing the area where the sample is located is arranged on the outside of the storage device. A data processing module is used to pre-process and chemically analyze the soil sample, detect the heavy metal signal intensity of the soil sample through an ion detector, calculate the heavy metal concentration in the soil sample according to the heavy metal signal intensity, evaluate the pollution level according to the heavy metal concentration and the heavy metal concentration standard limit, and send the evaluation result to the status warning module; A status warning module is connected to the data acquisition module and the data processing module respectively. The status warning module is configured to determine whether the area corresponding to the evaluation result is a sensitive area according to the evaluation result. When the evaluation result determines that the pollution level of the area corresponding to the evaluation result is too high, the area is set as a sensitive area, and the soil in the sensitive area is randomly sampled for a second time, and soil samples at different depths are selected for a second evaluation. According to the second evaluation result, the initial pollution level of the sensitive area is corrected to obtain a final pollution level, and whether to issue a warning is determined according to the final pollution level.

2. A heavy metal pollution detection system in soil samples according to claim 1, characterized in that: The pretreatment of the soil sample specifically comprises: The soil sample was dried at low temperature to constant weight, and then crushed into 200 mesh powder; Using microwave digestion, the powder sample was digested in a mixed system of concentrated nitric acid and hydrofluoric acid to completely dissolve the metal powder in the soil sample. The digestion solution was filtered through filter paper and diluted to a specific volume to obtain the dilution volume of the digestion solution. Prepare for chemical analysis.

3. A heavy metal pollution detection system in soil samples according to claim 2, characterized in that: The calculation of the heavy metal concentration in the soil sample by the heavy metal signal intensity is specifically as follows: Calculate blank signal intensity and instrument sensitivity correction factor; The calculation of blank signal intensity specifically includes measuring the signal response of a blank sample solution using the same instrument and conditions as those used to detect the soil sample; the blank sample is a reagent or matrix that does not contain heavy metals; The calculation method of the instrument sensitivity correction factor specifically includes: Prepare multiple standard solutions of different known concentrations to cover the concentration range of the sample to be tested, use an instrument to measure the signal intensity of each standard solution, and draw a calibration curve of concentration versus signal intensity. The slope is the instrument sensitivity, and the instrument sensitivity correction factor F is the reciprocal of the instrument sensitivity.

4. A heavy metal pollution detection system in soil samples according to claim 3, characterized in that: The heavy metal concentration in the soil sample was calculated by the following formula: ； in, Indicates the heavy metal concentration, Indicates the signal strength of heavy metals. Indicates the blank signal strength, represents the volume of digestion solution dilution, F represents the instrument sensitivity correction factor, m represents the sample mass, Indicates the sample volume.

5. A heavy metal pollution detection system in soil samples according to claim 4, characterized in that: The evaluation of the pollution level through the heavy metal concentration and the standard limit of heavy metal concentration specifically includes: The pollution level is divided by a preset gradient heavy metal pollution comprehensive index Pi, the heavy metal pollution comprehensive index is calculated by the heavy metal concentration and the heavy metal concentration standard limit, and the pollution level is determined by judging the size relationship between the heavy metal pollution comprehensive index and the preset heavy metal pollution comprehensive index.

6. A heavy metal pollution detection system in soil samples according to claim 5, characterized in that: The classification of pollution levels by presetting the gradient heavy metal pollution comprehensive index Pi specifically includes: Pi less than 1.0 indicates that the area where the current soil sample is located is free of pollution; Pi greater than or equal to 1.0 and less than 2.0 indicates that the area where the current soil sample is located is slightly polluted; Pi greater than or equal to 2.0 and less than 3.0 indicates that the area where the current soil sample is located is moderately polluted; Pi greater than or equal to 3.0 indicates that the area where the current soil sample is located is severely polluted.

7. A heavy metal pollution detection system in soil samples according to claim 6, characterized in that: The calculation formula of the comprehensive index of heavy metal pollution Pi is: ； Among them, Pi represents the comprehensive index of heavy metal pollution, represents the measured concentration of the nth heavy metal; is the standard limit value of the nth heavy metal, and n is the number of heavy metal types.

8. A heavy metal pollution detection system in soil samples according to claim 7, characterized in that: The secondary random sampling of soil in the sensitive area and the selection of soil samples at different depths for secondary evaluation specifically include: Sampling is carried out multiple times in the sensitive area, the average heavy metal concentration is calculated, and the comprehensive heavy metal pollution index is calculated again based on the average heavy metal concentration to obtain the secondary heavy metal pollution comprehensive index. The secondary pollution level is calculated based on the secondary heavy metal pollution comprehensive index. If the secondary pollution level is greater than or equal to the primary pollution level, an early warning signal is issued based on the secondary pollution level.

9. A heavy metal pollution detection system in soil samples according to claim 8, characterized in that: The calculation formula for the average heavy metal concentration is: ； in, represents the average heavy metal concentration. is the sample size, Represents the concentration of the i-th heavy metal in the j-th sample.

10. A method for detecting heavy metal pollution in soil samples, applied to the system for detecting heavy metal pollution in soil samples according to any one of claims 1 to 9, characterized in that: The method comprises: After collecting the soil sample, the soil sample is stored in a storage device, wherein the storage device is a pollution-free container, and a marking signal representing the area where the sample is located is arranged on the outside of the storage device; The soil sample is pretreated and chemically analyzed, the heavy metal signal intensity of the soil sample is detected by an ion detector, the heavy metal concentration in the soil sample is calculated by the heavy metal signal intensity, and the pollution level is evaluated by the heavy metal concentration and the standard limit of heavy metal concentration; Determine whether the area corresponding to the assessment result is a sensitive area based on the assessment result. When the assessment result determines that the pollution level in the area corresponding to the assessment result is too high, set this area as a sensitive area, conduct a secondary random sampling of the soil in the sensitive area, and select soil samples at different depths for secondary assessment. According to the secondary assessment result, correct the initial pollution level of the sensitive area to obtain the final pollution level, and determine whether to issue an early warning based on the final pollution level.

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